JP3702657B2 - Valve drive motor with improved sealing performance - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motor used in a valve that is interposed in a fluid conduit and closes the fluid conduit by a valve provided on a rotating shaft.
[0002]
[Prior art]
Conventionally, stepping motors are known as motors used for gas shut-off valves. The stepping motor includes a rotor having a shaft, a stator in which a coil is wound around the outer periphery of a yoke and the rotor is covered with a gap, a case for housing the stator, an opening in the case, and a rotor. And a lid on which a bearing for rotatably supporting the shaft of the rotor is attached, and a gas supply line when a valve attached to a portion of the rotor shaft protruding outward from the lid senses an earthquake. Is supposed to block.
[0003]
[Problems to be solved by the invention]
However, in such a conventional stepping motor, gas slightly enters the stepping motor from the gas supply pipe line through the bearing of the lid, and this gas flows between the coil windings, between the yokes or the stator. There was a risk of leaking to the outside through between the lid and the lid.
SUMMARY OF THE INVENTION An object of the present invention is to provide a valve driving motor with improved sealing performance that does not allow a fluid such as gas to leak.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, a valve driving motor with improved sealing performance according to the present invention as set forth in claim 1 is provided in the fluid pipe by means of a valve body provided in a rotating shaft, interposed in a fluid pipe line. A motor used for a valve for closing a path, a rotor provided with the shaft, a stator in which a coil is wound around an outer periphery of a yoke and covering the rotor via a gap, a case for housing the stator, it and a lid bearing for rotatably supporting said shaft of said rotor is mounted with close the opening of the stator, and the synthetic resin is Yes in the stator so that the stator has sealability It is integrally formed on the bottom cylinder, with the other end of the shaft is rotatably supported inside the loading cavity of the bottom section, Installing the cover to the stator via a sealing member And it is characterized in that it is.
According to a second aspect of the present invention, there is provided the valve driving motor according to the first aspect of the present invention, wherein the stator is integrated with the yoke by a synthetic resin, and the outer periphery of the stator is a coil. Is wound around.
[0005]
According to the first or second aspect of the present invention, the synthetic resin is integrally formed in the bottomed cylindrical shape in the stator so that the stator has a sealing property, and the shaft is fitted in the fitting recess inside the bottomed portion. The lid is attached to the stator via a sealing member so that fluid such as gas that has entered the motor from the fluid line through the bearing of the lid is wound around the coil. There is no leakage outside the wires, between the yokes, or between the stator and the lid. In addition, conventionally, since the gap between the case and the coil is a narrow gap in which only air is interposed, the coil winding may be broken by a lightning surge. In the present invention, when synthetic resin is integrally formed in the stator, If the outer periphery of the coil is covered with the synthetic resin, the synthetic resin is interposed between the coil and the inner peripheral surface of the case, so that the insulation performance is improved and the motor is prevented from being damaged by a lightning surge.
According to the second aspect of the present invention, since the stator is formed by integrating the yoke with synthetic resin and winding the coil around the outer periphery, positioning and fixing between the yokes can be performed accurately and easily.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a longitudinal sectional view showing an embodiment of a gas cutoff valve as an example of a valve according to the present invention.
In the figure, reference numeral M denotes a stepping motor (motor) according to the present invention, and this stepping motor M has a rotor 1 magnetized alternately in the circumferential direction on the outer peripheral surface 1A in the center. A shaft 2 is fixed to the central portion of the rotor 1. A stator 3 is arranged outside the rotor 1 with a slight gap. In the stator 3, a synthetic resin 5 is integrally formed by injection molding on yokes 4, 4 provided side by side in the axial direction of the rotor 1 to form a cylindrical bobbin 6. Coils 7 and 7 are wound around the outer periphery. On the inner peripheral surfaces 4A and 4A of the yokes 4 and 4, a plurality of pole teeth are arranged in the circumferential direction at equal intervals. Then, the rotor 1 is rotated by energizing the coils 7 and 7 and alternately exciting these pole teeth to different polarities.
[0007]
The stator 3 formed on the cylindrical bobbin 6 is formed into a bottomed cylindrical shape by further integrally molding a synthetic resin 8 by injection molding. The synthetic resin 8 is formed so as to cover the inner periphery of the bobbin 6 without a gap, so that gas does not leak between the yokes 4 and 4. The synthetic resin 8 is also formed on the outer periphery of the bobbin 6, and the outer periphery of the coils 7 and 7 is covered with the synthetic resin 8, but the outer end surfaces of the yokes 4 and 4 are exposed.
[0008]
A fitting recess 9A is formed in the inner central portion of the bottomed portion 9 made of the synthetic resin 8 in the stator 3, and this fitting recess 9A rotatably supports one end portion of the shaft 2 of the rotor 1. . On the other hand, on the opening side of the stator 3, a lid 11 that closes the opening is airtightly attached via an O-ring (sealing member) 12. That is, a ring-shaped groove 13 is formed on the end face of the synthetic resin 8 on the opening side of the stator 3, and an O-ring 12 is attached to the groove 13, and the lid 11 is bolted through the O-ring 12. It is attached by etc. A bearing 15 is fitted in the mounting hole 14 drilled in the center of the lid 11, and this bearing 15 rotatably supports the other end of the shaft 2 of the rotor 1.
[0009]
The stator 3 is accommodated in a bottomed cylindrical case 17, and the inner peripheral surface of the case 17 is in close contact with the outer end surface of the yokes 4, 4. A magnetic circuit of the stepping motor M is configured.
[0010]
The stepping motor M configured in this way includes a lid 11 and a flange portion 32 of the gas blocking portion 31 on a gas blocking portion 31 that is provided with an enlarged diameter in the middle of the gas supply line (fluid line) 30. By attaching a sealing member 33 such as packing and fastening with a bolt or the like, it is attached airtight. A feed screw 35 is formed at the tip of the shaft 2 protruding into the gas blocking portion 31, and a female screw 37 of the valve body 36 is screwed into the feed screw 35. The valve body 36 is prevented from rotating in the circumferential direction of the shaft 2 and is capable of reciprocating in the axial direction. As a result, the valve body 36 moves in the axial direction of the shaft 2 as the shaft 2 rotates. ing. A valve seat 40 is formed in the gas blocking part 31 in the pipe line 30 </ b> A which is the gas supply pipe line 30 on the side where the gas is put into the gas blocking part 31. The gas that has entered the gas shut-off unit 31 exits from the pipe line 30 </ b> B that is the gas supply pipe line 30 on the gas outlet side.
[0011]
In the gas shut-off valve configured as described above, the stepping motor M is activated when an earthquake is detected, and the valve body 36 moves toward the valve seat 40 when the shaft 2 of the stepping motor M rotates a predetermined amount. It sits on the valve seat 40 and closes the conduit 30 </ b> A that is a part of the gas supply conduit 30. In this gas shut-off valve, when the stepping motor M is rotated in the reverse direction, the valve body 36 is separated from the valve seat 40 and can be easily restored to the original state.
[0012]
In the stepping motor M configured as described above, the synthetic resin 8 is formed integrally with the stator 3 so that the stator 3 has a sealing property, and the lid 11 is attached to the stator 3 via the O-ring 12. Since the airtight attachment was made, the gas that entered the stepping motor M from the gas blocking part 31 in the middle of the gas supply line 30 through the bearing 15 of the lid 11 is between the yokes 4 and 4 or between the stator 3 and the lid 11. It is possible to completely prevent leakage through the outside.
[0013]
Further, conventionally, since the gap between the case 17 and the coils 7 and 7 is a narrow gap in which only air is interposed, the winding of the coil 7 may be broken by a lightning surge. Since the outer periphery of the coils 7 and 7 is covered with the synthetic resin 8, and the synthetic resin 8 is interposed between the coils 7 and 7 and the inner peripheral surface of the case 17, the insulation performance is improved. It becomes possible to prevent the stepping motor M from being damaged by the surge.
Furthermore, since the stator 3 has a structure in which the yokes 4 and 4 are integrated with the synthetic resin 5 and the coils 7 and 7 are wound around the outer periphery, positioning and fixing between the yokes can be performed accurately and easily. It becomes possible.
[0014]
In addition, although the case where it used for a gas shut-off valve was demonstrated in the said embodiment, it can use also for the valve | bulb of an air conditioner outdoor unit, a radiator hot water valve, etc., for example.
[0015]
【The invention's effect】
As described above, in the valve drive motor with improved sealing performance according to the present invention as set forth in claim 1 or 2, the synthetic resin is bottomed on the stator so that the stator has sealing performance. Since it is integrally formed in a cylindrical shape and the end of the shaft is rotatably supported in the fitting recess inside the bottomed portion, and the lid is attached to the stator via a sealing member, the fluid passes through the bearing of the lid. It is possible to completely prevent a fluid such as a gas that has entered the motor from the pipe from leaking outside through the yoke or between the stator and the lid. In addition, when the synthetic resin is integrally formed on the stator, if the outer periphery of the coil is covered with the synthetic resin, the synthetic resin is interposed between the coil and the inner peripheral surface of the case, thereby improving the insulation performance. Therefore, it is possible to prevent the motor from being damaged by the lightning surge.
Further, in the valve drive motor with improved sealing performance according to the second aspect of the present invention, since the stator is configured by integrating the yoke with synthetic resin and winding the coil around the outer periphery, the yoke There is an advantage that the positioning and fixing between them can be performed accurately and easily.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of a gas cutoff valve as an example of a valve according to the present invention.
[Explanation of symbols]
M Stepping motor (motor)
1 Rotor 2 Shaft 3 Stator 4 Yoke 5 Synthetic Resin 7 Coil 8 Synthetic Resin 11 Lid 12 O-Ring (Sealing Member)
15 Bearing 17 Case 30 Gas supply line (fluid line)
36 Disc

Claims (2)

A motor used in a valve that is interposed in a fluid conduit and closes the fluid conduit by a valve provided on a rotating shaft;
A rotor provided with the shaft; a stator in which a coil is wound around the outer periphery of the yoke and covering the rotor with a gap; a case housing the stator; an opening of the stator; it and a lid bearing is mounted for rotatably supporting one end of the shaft, and the stator synthetic resin to the stator so as to have a sealing property is integrally molded into a bottomed cylindrical shape, its Yes The other end of the shaft is rotatably supported in a fitting recess inside the bottom portion, and the lid is attached to the stator via a sealing member. Motor.   2. The valve drive motor with improved sealing performance according to claim 1, wherein the stator has the yoke integrated with a synthetic resin and a coil wound around the outer periphery thereof.

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